update version to 7.1.3

README

 PostgreSQL Data Base Management System (formerly known as Postgres, then
 as Postgres95).
   
-This directory contains the development version of 7.1.2 of the
-PostgreSQL database server.  The server is not 100% ANSI SQL compliant,
-but it gets closer with every release.  After you unzip and untar the
-distribution file, look at file INSTALL for the installation notes and
-file HISTORY for the changes.
+This directory contains version of 7.1.3 of the PostgreSQL database
+server.  The server is not 100% ANSI SQL compliant, but it gets closer
+with every release.  After you unzip and untar the distribution file,
+look at file INSTALL for the installation notes and file HISTORY for
+the changes.
 
 The latest version of this software may be obtained at
 ftp://ftp.postgresql.org/pub/.  For more information look at our WWW